But yeah, as therve says, can you convert the test to a unit test and the implementation into a unified diff? This page has some useful information about requirements for integrating patches, etc.

Not all of this should be going into one file. The fixed-offset timezone, for example, should probably live in twisted.python somewhere. For that matter, maybe the right way to implement that is to bring across the excellent Time class you did for Divmod and put it into twisted.python somewhere and use that for representing time objects on the wire.